1. Field of the Invention
The present invention is directed to a reflow furnace control system, and more particularly, to a control system for mass soldering reflow furnace.
2. Description of the prior art
In conventional furnaces used for reflow soldering electrical components to a printed board, control has been made to effect heating in a manner to obtain a preferred time-temperature profile of the board and/or the individual components as the latter moves along a conveyor line within the furnace. Such control is directed to several variables such as the transporting speed of the object, the operating temperature of individual heating elements disposed along the conveyor line, and therefore requires a number of steps for setting individual variables prior to running the reflow furnace. Further, since these variables will differ critically with differing conditional parameters including configuration and material characteristics as well as a required heating temperature of an intended object, the variable setting should be made in due consideration of the conditional parameters specific to the object in order to obtain an optimum time-temperature profile of the object and therefore can only be determined empirically after making a number of test runs. Such trial and error technique is obviously time consuming and cumbersome, causing undesirable loss of material such as printed boards, solder, and components to be soldered on the board. In a practical sense, the control of the reflow furnace is substantially possible only by a highly experienced person and not by an unskilled person, which poses a severe problem in its industrial application.